The present invention relates to a vacuum valve/sensor device, and more particularly relates to a vacuum valve/sensor device provided in a vacuum regulating apparatus which not only can measure the amount of vacuum, i.e. the amount of negative pressure, but also houses a one way valve which makes it possible to maintain a vacuum condition even when the vacuum generating apparatus is not being continually operated.
In the following specification of the present invention, and in the claims, the term "vacuum" will be used as meaning and including air at a pressure substantially depressed below ambient atmospheric pressure, for the convenience of description.
In prior art vacuum regulating devices, pressure sensors for measuring the vacuum value produced have been known to be incorporated, and thus measuring of whether the necessary degree of vacuum is being produced or not has been possible. Further, in prior art vacuum regulating devices, it is per se known to provide a vacuum preserving device, i.e. a one way valve for reducing the consumption of vacuum and holding said vacuum at a high level.
However, in such prior arts, because such a pressure sensor and such a one way valve have been provided as separate elements, the conduit arrangement between the vacuum regulating device and the vacuum generating apparatus, or alternatively between the vacuum regulating device and the apparatus utilizing the vacuum (such as a suction pad for lifting objects) has been required to be complicated.
Also, sometimes the vacuum condition or level maintained by the one way valve drops with the passage of time, due to leakage of air from such a vacuum utlizing apparatus or from some point in the conduit arrangment leading thereto. In such a case when such drop of vacuum level occurs, it must immediately be detected by the pressure sensor, in order for the vacuum generating apparatus to be again put into operation; since, if the proper level of vacuum is not maintained, the apparatus receiving the vacuum may malfunction--in the case of such apparatus being a lifting suction pad, an article or workpiece being lifted by the suction pad may be dropped.